Crane of structure: by driving points. One for the central drive Zhejiang 25 tons truck crane, which uses an electric motor to drive the long drive shaft on both sides of Active Wheel; the other for each drive that active on both sides of each wheel with a motor drive. Medium and small more using a combination of overhead crane brakes, gear units and motors into one of the "triple play" drive mode, the large overhead crane lifting capacity of the ordinary for ease of installation and adjustment, the driving device often used universal coupling . Crane Note: crane are not allowed to use supercharged. Allowed lifting case: Bundle is not strong; mechanical overload; signal is unknown; the oblique; buried or frozen in the ground thing; somebody was hanging on objects; there is no security measure is flammable, explosive and dangerous goods; too full of liquid items; wire rope does not meet the safety requirements; lifting mechanism is faulty.